Add Guild.change_voice_state to control our voice state.

discord/guild.py

@@ -2064,3 +2064,23 @@ class Guild(Hashable):
 
         limit = limit or 5
         return await self._state.query_members(self, query=query, limit=limit, user_ids=user_ids, cache=cache)
+
+    async def change_voice_state(self, *, channel, self_mute=False, self_deaf=False):
+        """|coro|
+
+        Changes client's voice state in the guild.
+
+        .. versionadded:: 1.4
+
+        Parameters
+        -----------
+        channel: Optional[:class:`VoiceChannel`]
+            Channel the client wants to join. Use ``None`` to disconnect.
+        self_mute: :class:`bool`
+            Indicates if the client should be self-muted.
+        self_deaf: :class:`bool`
+            Indicates if the client should be self-deafened.
+        """
+        ws = self._state._get_websocket(self.id)
+        channel_id = channel.id if channel else None
+        await ws.voice_state(self.id, channel_id, self_mute, self_deaf)